Any drift noticed on vCenter when you run w32tm /stripchart /computer:<NTP server>?
Perhaps ensure that the domhier server that vCenter is using for NTP sync is the same as the ESXi servers and analyze to see if the NTP daemons are running automatically on the hosts.VCDX #104 (DCV, NV) ஃ WahlNetwork.com ஃ @ChrisWahl ஃ Author, Networking for VMware Administrators1 person found this helpful
Thanks for the reply. I think we have finally resolved it.
The PDC emulator is using the same NTP server as the ESXi hosts and there appear to be no issues there.
In the end I went with my theory that vCenter was configured with too many vCPUs, reduced it to 2 x vCPUs to reduce the likelyhood of CPU inactivity timing issues and since then we have not experienced the initial problem.